We need an API to clear the message bar at the top of the UI, but not clear out any messages from the message center (i.e. need an API that does the same thing as when you double-click the message in the message bar - just remove the message from the screen).
CoreGUI.getMessageCenter().reset() will clear all messages in the message center, as well as clearing the message bar, so it would be too heavy handed.
CoreGUI.getMessageCenter().notify(new Message("", Message.Severity.Blank,EnumSet.of(Message.Option.Transient)));
is the only way I know of to clear just the message bar. It is obviously quite convoluted, so we should really add an intuitive API for clearing the message bar, e.g.:
CoreGUI.getMessageBar().clear();